The present invention relates to a door frame of a shaft door with a control arrangement for an elevator shaft, as well as to a method for access to a control unit.
A control arrangement in the sense of the present invention substantially comprises a control unit and means for mounting and protecting the control unit. The control unit in turn substantially comprises subassemblies required for control and/or regulation of the elevator installation. Moreover, such a control unit can contain interfaces and input modules necessary for servicing the elevator installation and for diagnosis. The control unit accordingly has to be accessible for the purpose of servicing or maintenance of the elevator installation.
Previously the control unit of an elevator installation was usually accommodated, together with the drive of the elevator installation, in a separate space or region, since such a control unit was, depending on the respective form of construction, relatively large.
A separate space is superfluous with present-day elevator systems, since the drive is frequently arranged in the elevator shaft itself. In the case of elevator installations of that kind the control unit is advantageously disposed in a region of an elevator shaft closure. European patent document EP 0 680 921 discloses a corresponding arrangement of a control unit in the wall of an elevator shaft. This arrangement demands a large space, since a control box is attached to the shaft door frame. Since this control box is usually needed on only one floor, this necessitates special constructional and aesthetic solutions for this floor. This is made possible inter alia by the fact that present-day control units are smaller and power consumption as well as generated heat could be reduced and thus, for example, space-consuming ventilating installations are not required.
The prior art control unit is preferably accommodated in the door frame, in a chamber. Such a chamber is formed by, for example, a door frame element of the shaft door, usually by a vertical door post element. The door post element has walls which bound the chamber. One of these walls has an outside opening which opens outside the elevator shaft and thus at the floor. The wall of the door frame element having this outside opening lies substantially parallel to the door leaves of the shaft door. The same wall generally also has a passage in which a floor panel is arranged by way of which the users of the elevator system can call the elevator car.
It is disadvantageous that the door frame element with the incorporated control unit visually differs from the door frame elements of the remaining floors not requiring control units and that different built-in floor panels result. A solution for placement of the control unit that would make it possible at the same time to use the same floor panel on all floors would be desirable.
PCT patent application WO 03/072478 shows a corresponding incorporation of energy supply units in a door frame. The energy supply units are accessible for maintenance, from the floor, via a pivotable lid. A disadvantage of this arrangement is that the openings, which are to be provided, in the door frame are executed to be large so that all work, such as, for example, replacement of apparatus, can be undertaken via these openings. This again requires a cover of large size, which is costly and unattractive.
The control unit itself is not visible when the elevator installation is in normal operation. It is disposed in its operational position. Access to the control unit is required within the scope of service or maintenance operations. If within the scope of service operations at the elevator installation there has to be access to the control of the elevator installation, the control unit is brought into a service position. The control unit has to be visible in this state and the actions required for servicing of the elevator installation, such as, for example initialization of travel commands, interrogation of state data or actuation of switches, has to be able to be carried out. If more extensive maintenance operations, such as, for example, replacement of components of the control unit, are required an appropriate degree of access has to be ensured. The difference between service operations and maintenance operations resides in the fact that for the purpose of the service a limited access to the control unit is required and no greater space for that purpose is necessary. Thereagainst, within the scope of maintenance of the control unit in certain circumstances parts have to be replaced, for which purpose a correspondingly large access space is necessary.
The outside opening of the chamber can be closed by a cover. The cover can, for example, be pivotable in the manner of a door leaf. In an operational position the cover closes the outside opening and in a service position the cover frees the outside opening and thus access to the chamber of the control unit for the purpose of service and maintenance. In a known solution the control unit is, for example, connected with the cover of the outside opening and is pivoted in common therewith.
It is disadvantageous with this solution that such a cover is large and correspondingly visible, because the service and maintenance operations have to be carried out through the outside opening.
The following point is to be regarded as a further disadvantage. The control unit of the elevator installation is typically supplied with mains voltage or three-phase current. If the control unit is seated in a door frame with a pivotable cover or it is fastened at this cover the risk then exists of the mains cable being crushed and damaged. A danger is thereby created. In the most unfavorable case the door frame or the shaft door can be shorted to the mains voltage.
In addition, the use of special flexible cable and the associated connecting elements for the control unit increases costs.